The RAM-B-107-1U, powder coated marine grade aluminum mount, consists of a double socket arm, one 2.5" diameter round base and connecting Humminbird/Eagle/Lowrance marine base. The mount is designed with a 1" diameter patented rubber ball and socket system that has adjustment points at the cradle base and bottom base. With a twist of the arm knob, you can move the marine mount to your optimum viewing position.